1. Field
The inventive concepts relate to methods of manufacturing a semiconductor memory device, and more particularly, to methods of forming a bit line and a storage node contact (SNC) of a semiconductor memory device.
2. Description of Related Art
As the functionality of a microprocessor becomes more powerful and a software program of the microprocessor becomes more complex, demand for larger capacity dynamic random access memory (DRAM) accordingly increases. An increase in the integration of DRAM results in a reduction in the size of a DRAM capacitor. The surface area of the DRAM capacitor necessarily increases in order to maintain capacitance of the DRAM capacitor. Thus, stack type capacitors have been developed.
With respect to a capacitor over bit line (COB) (which is a stack type capacitor), an increase in the integration of the DRAM results in a reduction of an overlay margin between a storage node contact (SNC) and a bit line. Such a reduction makes it difficult to form the SNC and a bit line.